Yeah you could do the spring only lift but you might have issues with your rear shocks topping out. It would also be a pain in the *** to keep the front shocks and then upgrade once you get the money because you will essentially be installing a lift twice. I just don't like the idea. You'll be fine on stock suspension until you can save up for an OME lift.
A good idea might be doing a clevis lift until you get the money saved up for a full lift.
Also user 'crippled' over on LOST is selling a complete OME lift with only about 500 miles on it (don't ask why...
) you might want to send him a PM on what he's asking for it