Having just done this for my 99:
You will need a front axle bracket kit which includes a mini-truss of some kind to locate the one control arm on the "top" of the differential, along with the other control arm brackets, coil spring mounts/shock mounts.
On the back, you will need the coil spring mounts, shock mounts, control arm mounts and track bar mounts.
There are a couple companies who offer "kits" to swap axles into a TJ. The rear "kits" vary from ~ $300-600. When I searched, there were not a lot of companies who offered a complete front kit. Teraflex was on company, but the front "kit" was on the order of $600.
You could theoretically cut off some of the brackets from the existing axles and re-use, but you would probably be better off to sell the existing axles with the factory brackets intact as without them they will be basically only worth scrap metal prices.
All of these kits require a significant amount of welding, and you are welding your axles to your suspension, so you should consider the significance of a poor weld when you are driving down the road at 70 mph. My local fabricator quoted me ~ $450 per axle to weld everything and install them.
One thing to consider is whether you want to put all of that effort into fabricating mounts and leave it as a stock suspension. My Jeep had a 4" Teraflex lift with 8 adjustable arms, but I knew at some point I would want to change that out - at which point all of the money spent on welding the stock brackets would be wasted
So I decided to go ahead and bite the bullet and went to a 3-link front and single triangulated 4 link rear, but still use the springs and shocks from the 4" Teraflex lift. My fabricator put together a mix of components from Teraflex (front truss), Poly Performance (rear truss) and Ruff Stuff (heims, control arm brackets) which turned out very well. It cost more to do it this way (~ $5K total installed), but now it's a fairly small step to coil overs. - Just something to consider.