Normally id suggest AFDP for you but I don’t think it is a good Helicopter sim at all.

The only other sim that I have tried myself would be G3, it has better Helicopter physics IMO but still not perfect.

If you went with G3 you would probably get good frame rates just by getting a used $50 video card off of ebay.

I bought a Radion 9800Pro off ebay for 60 bucks a long time ago (so there probably cheaper now) and it works pretty well with G3.