What would be better to get in shape for rugby/mma?

Next fall semester i plan on trying out for the rugby team and if i dont make that i will start mma.
I havent done much in terms of exercising this semester other than going to the gym a few times a week pretty inconsitatnly to run.

Basically i planned on doing a body builder type workout for a month over winter break just to kind of get back into lifting and such and then planned on doing either mark ripptoes starting strength or the stronglifts program once i got back to school.
for my winter break workout it is monday wednesday friday lifting (monday and friday are upper body and wednesday is lower) stuff like curls and pulldowns and stuff like that. this is just to get back into lifting somewhat into better shape. i know its mostly superficial type exercises for bigger arms. i just dont have the equipment to do the good stuff like deadlifts and squats. and then tuesday and thursday i planned on running.

however my friend just showed me this crossfit stuff she does and it looks real legit and i want to somehow incorporate it.

my question is what would be better…focusing on getting bigger by mostly lifting weights or doing crossfit in which i will be lifting weights and running and all sorts of stuff that will make me hate my life.

How should I prepare for mma?

Im gonna start mma around july because we are moving to fort walton beach this summer. And i was wandering how I should get in shape for it. Im doing crossfit now and lifting weights, I have some boxing gloves and wraps. What other stuff should I be doing to get ready? Im kind of a big kid, Im 6’2" and 198 pounds and Ive got fat to lose. So also what diet is good for mma? Paleo?