Best transmission line kits for monitoring

Hey guys! I am upgrading my studio soon. With the new room design it's time to move on from my Focal CMS' to a full range pair. I am a bit of a bass head and am intrigued with the concept of transmission line speakers. But hey, PMC full range monitors are almost as much as the drop in value of my house (recently sold our house...ouch). So I am looking at DIY options. Does anyone here know of a good DIY kit (with crossover etc) for mixing/mastering.