That depends on you and your level of flying.

The Sig Somethin' Extra is a VERY Aerobatic AC it is not a model for beginners - yet here we are in the 'Beginners' Forum discussing it.

The 6.5 ccm Webra engine will fly a 40 sized SSE and as such you will be happy in the beginning as you master the AC and it's capabilities.

Once you feel confident with this, you will have the option to 'up' the engine to expand your abilities. You will have to expand your wallet too.

This $26.00 Webra will be a great starter, after that you may consider a 46 or 52 sized engine that is tuned for more power - but don't be in a hurry - plenty of planes have died from people trying to go too fast, too soon. [&o]

Good Luck!