I am sorry if I was imprecise, I was referring to the entire end-to-end process that includes obtaining the service kits, and from the perspective of someone who is not connected in the scuba industry, and has no special access channels. I heard that service kits for Apeks are much easier to source. I have no idea if that is true, I really hope not, for I would really love to be able to service my trusty old Titan LX Supremes completely on my own. I would be grateful if you could nudge me in the right direction...
It should actually not be too difficult to service your old TITAN LX SUPREME, if you have some basic knowledge concerning servicing regulators.
Since the Legend 2nds and the Titan 2nds are almost identical, you could check also for a Legend service kit.
Usually there are no o-rings which have to be changed absolutely if they still look okay after cleaning and lubricating. If you have a selection of generic o-rings from 003 - 022 you should be fine. You would have to check the small o-ring at the shuttle valve by sticking the end of the shuttle valve together with the o-ring (lubricated) into the counterbalance chamber (without spring). Then close the hole in the LP seat with your thumb or a finger and press the shuttle valve down into the balance chamber. If the o-ring is still okay, you should feel a resistance and the shuttle should return back up, because the air cushion in the chamber will be compressed, pushing back the shuttle in its original position.
So the issue would be probable to get a low pressure seat.
If you don't find a service kit, you could check for Scubapro LP seats for the G or S series, they are using the same seats ( or at least they show no difference in performance), or you get yourself one of the Trident seats (A148).
They work on the Aqualungs, but not so good on the APEKS 2nds.
Concerning the first stage most important is that you find a HP seat (105940). Those seats are also used in the Legend series and others. If you have access to Mares parts, they are using the same seats in their MR12 series for example.The seats offered byTrident are substandard to my opinion, I cannot recommend them.
Last problem might be to find a new filter, but they are the same like in the Legends and they are also used in some TUSA 1sts.
I would not hesitate to reuse them after cleaning if they don't look too bad.
If you need the Service manuals, pm me, I guess I can get them for you.
Good luck.....