what do i need to build a lpg gas research setup? engine wise, bigger rods? or would a standard a8 be fine?

A8 will be fine even an a6 will be fine... All depends how far u wanna go... And of corse depends on how good ya tuner is

If you want to build a performance LPG car go to someone thats done it before. Everyone thinks its easy, then again look at why there arent many perfomance LPG cars. Clearly its NOT easy and unfortantly most people that try end up failing Anyway if you need a hand let me know, Tunnel Vision built mine that has run 9.52 @ 147.78MPH and built a 4ltr mustang that went 8.98 @ 155mph both on straight LPG. Some original photos have not been recovered yet.

what would i need to make 300rwkw or more in the future?

A setup similar to mine with the gas system! Take it to tunnel vision and let them do the job Some original photos have not been recovered yet.

do you have a standard tank modified? twin lines run to 2 separate convertors which join into one into the throttle body/mixer?

Would be best to let tunnel vision to do the whole job if you want it done right

will give them a call, anyway does yours run water/meth injection with the gas?

Usually run water inj although its not connected atm