If you are looking at going down the tech route and want to do it in SM I say the earlier the better. One thing to consider is where you will be diving. Here in the US especially in FL most of the cave diving is in steel cylinders. Having a SM rig with enough lift to move through the various parts of cave diving such as steel cylinders, stages, etc. would be optimal. The Stealth can be setup for this type of diving but requires more fine tuning than others available.
Also doing some comparison shopping of instructors and facilities would be a good thing. Give Edd Sorenson @
Cave Adventures a call and find out what his pricing is. I have known Edd for a long time and is at the top of my list as instructors and SM instructors. I have not taken any classes with Edd but I have audited a few of them and worked with his students after they have taken classes with him.