Transceiver
A good transceiver is the basis of the station. On 2m, this can be a radio with VHF and UHF capability. I use several Kenwood TS-2000S and TS-2000X radios. Any modern radio with low internal noise and a clean transmit signal will do well. It is helpful to have a radio that can use external ALC depending on the amplifier and sequencing system used. This radio is also nice or remote control operation using a RemoteRig and the Kenwood RC-2000 controller. The Icom IC-706Mk2G has similar very easy remote capability over the RemoteRig but is more prone to drifting as it warms up.
A good alternative is an HF radio with a transverter. The Bonaire station is being upgraded to a Flex Radio 6400 with a 2m transverter from Transverters Store. Higher performance transverters will perform better but are out several dB over budget. Experiments are underway using a QRPLabs ProgRock with GPS locking as a frequency reference for the Flex radio and the transverter.
Amplifier
Life is too short for QRP, especially when researching uncharted propagation paths, so a power amplifier is very helpful. The amplifiers at N7BHC and PJ4VHF stations are currently all based on modified Larcan television modules. They are available in 600W, 1.0kW, and 1.5kW versions. All are rated at 100% duty cycle in 24/7/365 television service, so running high duty cycle digital modes at full power is no problem at all. I run a 1kW version on 6m, and a 600W version modified onto 2m.
The amplifier modules is just part of the amplifier. It also needs a case, power supply, and control circuits. I have found the excellent line of products from Jim Klitzing W6PQL to be invaluable in building your own amplifier. If you reference the articles from the 2018 Central States VHF conference on my files section, you will find the published article and PowerPoint presentation I presented on on modifying and building a 600W amplifier using the Larcan I{A2 driver stage. The mod is very simple, and much of the article is how to use the W6PQL modules in building your own amplifiers of 600W - 1.5kW.
Larcan Amplifier Modules for Sale: I have several 1.5kW and 600W modules for sale. These are currently suitable for use on 6m just with minor tweaking. They are also both modifiable to 2m (or even 4m for the Europeans). See my For Sale section for current stock levels.
W6PQL amplifier: Jim also produces an excellent line of amplifier kits for HF through 1296 MHz. I highly recommend his products as well. They are physically smaller than the Larcan amplifiers and cost more, but are very nice. They are also available as completed products.
Commercial amplifiers are also available from a number of manufactures in the 500W-2kW range. I have no experience using them personally. The main thing to watch for is the duty cycle capability. My experience with amateur amplifiers in the 150-400 Watt level is that they had to be derated for digital modes or one runs the risk of severe damage.
Antenna System