I would go for the stage 63 bonus extreme, where the high performance 40" boat was upgraded from a .12 nitro to a high performance 550 size mabuchi, then further mega-upgraded to a brand-x gas engine, then taken to extremes and upgraded to a high performance 110,000kv brushless motor that will produce an estimated 2376mph.

Ok, ok ,I got carried away, I do get a laugh whenever I read their listings. Scary part is people are buying them.

Everything they sell can be bought from vendors such as hobby king for half or a third what they charge.
If you ask a few questions here you can find out what you actually should buy.