There is a company that makes a installation kit for the axle swap,all bolt on.i already have a 8 lug 14 bolt for the rear,haven't put it on yet,waiting for front axle.The truck is a daily driver that i take wheeling on the weekends.
By the sound of it, you've got most of the bases covered already. Other than the obvious point of making sure the gear ratio in the front axle you get matches the rear one you have now, I can't really add a whole lot - my experience is with the 73 - 87 trucks.
I take it the reason the "F-word" ( ) axle is required is to have the "pumpkin" on the proper side to match the '98 transfer case?
I have a buddy that converted his 99 tahoe to a straight axle in the front, with dana 60 front off a "f"word. First we had to torch, grind , and remove off all the old IFS bracketry, watch out for the brake lines, then when it was down to just pure frame, We had to custom make brakets for the front of the leaf spring mounts to the frame and drill holes in the frame to mount the (rear) front shackles . My buddy oppted for Crossover steering at the same time, and when everything was said and done he had about 15" of lift with 39.5 boggers, I'll try and get a picture uploaded.