My friend has started playing x wing and has the YT-2400, the starting kit, and a rebel aces b-wing (no a-wing). The aces b wing has all pilots and the b-wing e2 title and ion torps. He is wondering what to get next for a ship and since I'm still some what new to x wing I don't know what to tell him. Any help is appreciated. Thank in advance.

Which starting kit? Original or Force Awakens?

Also are you okay with proxying, meaning printing out cards or otherwise using placeholders? It's much cheaper to buy expansions for the ships and and just proxying the cards; usually the only time you need to own the cards is tournaments.

IMO the ARC-170 goes well with the YT-2400, but so do a lot of things. It's also a fun ship to fly.

Nera makes a strong pilot with the right torpedoes, especially with Biggs by her side.

Heroes of the Resistance is a great expansion if you like the Millennium Falcon & T-70 X-Wings.

He got the force awakens starter kit. And thanks for the help!

Well, with a small collection like that, I would make a few suggestions:

For the "I only want to fly Rebel" type I would suggest first, buy a ship that looks like fun, cuz you can proxy cards, but you really kinda need the right ships. Pick something that makes you happy to look at, cuz no matter what you get, there will always be something else that needs to be added. For competative purposes, I would suggest the Heroes of the Rebellion. Comes with several cards that can make t-65 and t-70 x-wings more useful. If you have the TFA starter, I would also get the t-70 blister so you/he can fly triple T-70's with any pilot option and 3 ships.

For the "I want to dip my toe in IMP life" I would get the tie blister that matches the ties in you starter and probably either Imp aces or Imp Vets for useful cards, pilots and the option of a decent mini-swarm with an ace or something like that

Heroes of the Resistance, 1 millennium falcon, 1 t 70 x wing. comes with some neat pilots and upgrades: rey, finn, poe PS 9, jess pava, black one title. go get...!