Important Note
None of these answers should be taken as official in any way.
Q: English language support?
Official English localization is an unlikely probability because the series already has more of a cult following in Japan (meaning not as mainstream as say Hatsune Miku: Project Diva), and the following outside of Japan is even more of a smaller niche. What I mean is the franchise does relatively well, but I don't think this particular game genre (with its alcohol focused hostess club game play) is an easy decision to localize. Plus from a business perspective, the expenses to properly localize them would not be justified for the potential revenue from the initial point of sales, and then DLC sales. Subbing on the surface seems simple but there are on screen space considerations as well as timing issues (anyone who has done fansubs will understand what I'm getting at). Voice work (dubbing) is even more expensive because of the costs associated with voice actresses, and there is a lot of dialog (especially subtle jokes) as well as "lost in translation" considerations that make that route less attractive for games like this.
However, with games like Akiba's Trip 2 and Omega Quintet being localized for release outside of Japan, who knows? The biggest difference is these two games have an ARPG fighting element to them which have a lot more appeal than dating style sims. Note that Omega Quintet's Promotion Video System is reminiscent of the karaoke aspect in Dream C Club, but with more control (so it is something that appeals to people like myself.)
Q: Will they bring any of these prior console game series to the PS4 and Xbox One?
Frankly, no one except D3 Publisher knows at this point. They might just continue with the successor to Gogo for example (which was PS3 only.) Another consideration is the better capabilities of the newer consoles; just re-hashing the prior games and tacking on additional content (as was done when Dream C Club Zero for the Xbox 360 was brought over to the PS3 as Special Edipyon!), is probably not going to cut it. Talking to people more familiar with development, the developers might be trying to determine how to bring the franchise forward onto the newer consoles when it comes to the game play aspects. On the PS4, part of the work has been done (with the karaoke and costume coordinate in Host Girls on Stage).
Q: Will Host Girls on Stage have the hair arrangement and accessories customization found in the dating and hostess club sim games?
In my opinion, they would have added these in from the beginning as DLC if they wanted to capitalize on sales. Then until August 2014, they released only costume DLC's (most all of these are outfits that were also available in Dream C Club and Dream C Club Zero.) So I'm presuming they aren't planning to add that in due to the amount of time that has passed since the February 2014 launch. Again, talking to others more familiar with development, the developers probably are working on the next game in the franchise for PS4 and Xbox One as opposed to putting anymore development resources into designing the user interface and programming the code for those type of customization in HGOS. Originally, HGOS was supposed to have the ability where the player could buy the host girls drinks via tickets that would be purchased as DLC similar to how PureClock Amane works. That never materialized though (I personally don't think the concept went over well with PureClock Amane though which is probably why they did not go that route.)
Q: What do you think the next Dream C Club game will be like?
I really have no idea. Keep in mind the developers have not said anything official about a game for the franchise on the PS4 and Xbox One. They have pretty much had one game on each platform (including portable PS devices, Android, and iOS) so it logically makes sense they are probably working on one right now. IMO, it's not a matter of if, but more of when. And when you think about how much more power the PS4 and Xbox One consoles have, there is a lot more they could do. Tamsoft has also gone on record in several interviews that developing for both consoles is much easier compared to the PS3 and Xbox 360. Myself, I'd like to see less turn based play and more real time interactivity beyond what currently exists.
As for the host girls part, what they plan to do will be the most interesting. There is no denying the original DCC and DCC Zero host girls are more iconic to the franchise compared to the new ones introduced in DCC Gogo, and the ones that were introduced in the short-lived Host Girls Collection card game. I'd like to see all of them brought together under one game with more advanced game play including an open free play mode that sort of works like the VIP unlock.