And I'm 18, so just word of the wise, save your money and just buy a really nice lift kit. Do it right the first time so you don't have to do it again and again with cheap parts. Biggest mistake I made

 

The more research, planning and saving you can do, the happier you'll be and more badass your XJ will be in the end. IMHO, 4.5" LA on 33's with some trimming is a damn good set up. As stated, there's a lot that goes into a GOOD lifted rig. You can achieve a lot of lift with minimal work/money, but it will probably suck..

 

You know it man! Do it once, do it right.

 

Do long arms. 4.5" is OK on short arms..but spend the extra bit of cash so you dont have to do it later. Ive had 4.5" short arms on my last 2 jeeps..not a bad setup..but far inferior to a long arm setup. My new build is going to be at 4.5 but with a 3 link setup.
Buy QUALITY stuff....dont cheap out..youll pay for it later.
At 4.5 your gonna need;
The obvious: Coils, leafs (preferrably leafs and shackles), LCA's (either short, short with drop brackets, or long arms), trac bar, and with 33s maybe an upgraded steering setup.
If your gonna run 33x12.50s find some wheels with 3.75 backspacing..or so.
Your gonna need to trim unless you want to scrub the **** out of your tires with each turn and bump..ive done 4.5 and 33s with NO trimming..it sucks.

Be prepared to want an SYE..tc drop's suck..at least get a Hack N tap.
Oh..bumpstops will be your friend.

 

Just gonna say the same thing. Bump stop, bump stop, bump stop!