conversion help please

my CRT Truggy conversion is coming along....here is a parts list so far...
i have the RCM motor mount
in route is the Neu 1515/2.5d/f and the Monster max ESC and a couple of 46t spurs
i'm making a list now for RCM...
i was curious if it would be a good idea to run the RCM front motor cover and rear motor endbell cover i see on the site??
besides a couple of pinion gears( 11 and 13 ??) and working out the battery trays is there anything else i should be ordering that i'm missing ??
I'm pretty sure i will go 5s but can i go 4s if i want?? (this will be mainly a racer,not a basher)...any battery suggestions (i'm hoping to run a single battery set up)
thanks for any help and suggestions

[Arct1k]

5s would be better on a 2.5df 1650 KV - the polyquest, flightpower 5000s would be great if you can afford

The only other thing you havn't mentioned is a good rx or servo...

The front and rear cover are nice but not essential - some do some don't.

thanks for the reply ...as far as the rx and servo ...i will be using the Airtronics 94359 servo and the spektrum DX3r for radio gear....i'll check out those battery choices ....thanks again

Any of the batteries with enerland cells are good. I have had good luck with TrueRC and Zippy for the cheaper ones.

as far as pinion gears go ...i see a few different types.....with either the stock metal CRT spur or the KYOSHO nylon spur ...which type do i need?....will both spurs use the same pinions ? thanks again guys for the help