A LIM from any Series 2 L36 will fit your engine. That'd be 95+ Bonneville, and 96+ LeSabre / Park Avenue. (For Grand Prix and Regal, it'* also 95 or 96+, not sure exactly the cutoff)
The only difference is that in around 99/00+, the EGR stovepipe in the LIM was reduced from 3/4" OD to 5/8" OD. If you happen to buy an APN UIM kit, it will have both sizes of replacement stovepipe.
I do still have a junked LIM you could have for practice, you just pay shipping (or additional shipping, as the case may be
If you buy a Junkyard LIM instead, be sure to check it carefully for pitting and warpage on the LIM-to-head surfaces, and that none of the bolt holes are stripped.