Hi currently own a hpi nitro rush with standard .15fe engine and looking to get a bit more power in it was looking at

hpi g3.0 - http://www.hpieurope.com/kit-info.ph...p;partNo=10411
or
the O.S. 18TZ-TX w/Rotary Carb - http://www.rcplanet.com/O_S_18TZ_TX_...p/osm11943.htm

my main issues that i am new to nitro rc and bit unsure. both engines high power 2.2 and 1.8 respectively but the hpi costs bout £50 less with more power is it really better and more importantly can a hpi rush handle that kind of power without ending up with a twisted chassis or broken gears? which leads to my next question what parts would need upgrading to cope.

Any suggestions gladly recieved also if anyone has a rush and has pics would love to see what i aspire to