I would like the recomendation of you people about buying the US enginies.

I have seen the 25 , 35 and 45 cc engines ina catalog and found them really cheap.

are these worth to buy ? i am most interested in the 35 CC .
are the relaible ? I want to use them just for sport flying ........ i.e just for flying bigger sized aircrafs.....

secondly another important thing i want to ask is that can these engines work for me in a pattren plane ? or in a 3D plane ?

I cannot spend more than about $250 for an engine .... and i found that US engine is better than converting some other engine. please tell me about any alternatives if possible.

And Please help me in making it clear for me which engine to buy.

Thanks in Advance
Usman.