As far as I know, Waterproof factory installs the Si-Tech's QCS Oval wrist ring system and one of Si-Tech's integrated neck ring systems (Necktight or Quick Neck ring system)....the difference is that Waterproof has their own brand of neck and wrist seals.
I have sets of both Si-Tech and Waterproof neck and wrist seals. From the looks of the seals, I would bet they are made by the same company by either Waterproof or Si-Tech, or both are sourcing from the same 3rd party provider. That being said, I prefer the the Si-Tech brand wrist seals as they are a touch thicker and feel more durable, I also prefer the bottle-neck shape of the Si-Tech wrist seals over the shape of the Waterproof branded ones.
For neck seals, Waterproof has weird bellows designed into the back of their silicone neck seal....I have yet needed to use the Waterproof neck seal in my stash of spares, but it seems to me that the bellows is unnecessary and just a way for Waterproof to make their product standout.
Bottom line is that Si-Tech and Waterproof neck and wrist seals are completely interchangeable. I don't know of any other brand currently marketing silicone seals at this time.
Prices tend for silicone seals from either brand are almost double in the US than they are from European sources, so when shopping I would encourage one to look for overseas sources to save some money.
As far as gloves go, you can use any manufacturer's glove on the Ultima DGS, but in order for a water tight seal, you need a smooth surface from the glove to be in contact with the glove-side ring of the Ultima DGS. For gloves with flocking or lining, this entails folding the outside of the glove's cuff inward over the retaining o-ring and then strech the glove and o-ring over the glove-side ring so the smooth surface of the glove is making the seal against the ring. This can be quite challenging with the glove retaining o-rings that Waterproof include in the Ultima DGS kit.
I am partial to the SHOWA 720 gloves. They are an unlined, nitryl dipped glove, with acrylic flocking on the inside. You can call SHOWA directly and request models and sizes of gloves you want to try and they will ship them to you for free...once you settle on model and size, it is inexpensive to purchase spares/replacements via Amazon or Ebay.
If you go with a SHOWA glove or a glove that you need to fold over the retaining o-ring, I highly recommend you purchase a couple of size 341 x 70 durometer (BUNA) o-rings to replace the o-rings in the kit for retaining the gloves, it will make it vastly easier to install gloves on the rings and will not sacrifice retaining strength. You can thank me later for this tip.
If you have not already purchased the Ultima DGS, I recommend looking at the Ultima DGS Twist...this is essentially the same as the Ultima DGS but the glove rings have extended tabs around the circumfrence that are use to aid in prying the glove rings apart from the cuff rings. There is also the Ultima Push-Pull accessory that can be installed on the glove-side rings that make it easier to separate the two halves of the system, especially after a dive when one's hand might be cold and one wants to get out of their suit quickly to relieve bladder buildup:
Regular Ultima rings:
Ultima Twist rings:
Ultima Push-Pull ring accessory:
Also, note that while the Ultima DGS is a great glove system, you are not limited to that product. Some of us have migrated to the Rolock 90 dryglove ring system. This system is designed to readily integrate with the cuff ring of the Si-Tech QCS oval wrist ring system, and will work with the drysuit you purchased. The Rolock 90 works as well or better than the Ultima DGS, but its main advantage is that it is easier to set up and takes less effort to don/doff.
Good luck with which ever system you get, and don't hesitate to ask more questions as they pop up.
-Z
