Intel/Altera and AMD/Xilinx are the two big name FPGA providers, but their chips are a bit expensive.  Gowin is a Chinese manufacturer of FPGAs, but none of their boards have yet grabbed my attention.  The open source community is strongest on the Lattice boards,  so a lot of people like to use them, and build boards for them. Here is the list of all of the boards supported by the open source software apio.  For the low end Lattice FPGAs, the PicoIce and Upduino have a good reputation, so I am starting with the Upduino and moving to the PicoIce. For the mid range Lattice ECP5 range, the ULX3S has a good reputation.  And he ULX4M is soon to be released. 

What is the difference between the PicoIce, and the Upduino? The Upduino is really just an FPGA.  Yes there are chips for USB connectivity, and flash,  but to the developer it only looks like an FPGA.   The Pico-Ice also has an RP2040.  This is the very popular chip at the heart of the Raspberry Pi.  It does a lot, but it also adds a lot of complexity.  The RP2040 comes with a C firmware but it also boots ZeptoForth, and it probably also boots MicroPython and Mecrisp.   And with great power comes great complexity.  What features are enabled at any point in time on each of those platforms is changing very rapidly, so I will not say more here, please join the discord server to find out whether your needs are currently met or not. 

One friend recommended the following.

https://www.tindie.com/products/johnnywu/icesugar-pro-fpga-development-board/

https://docs.lambdaconcept.com/ecpix-5/_images/ecpix5.jpg

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