I am wanting to convert my Jet 1100 dust collector to 2 stage. I see a million prices and options for the dust deputy. Do I need the large XL model or the one with 4" pipe fittings.

Thanks very much that answers one of my concerns. I will be ordering one very soon.

Since the Jet 1100 has a 6" port with 4" adapters, you could likely use either Super Dust Deputy cyclone. Since the 4" model only comes with the 15 gallon drum, take that into consideration when choosing a product for your shop. The 15 gal. will fill quite quickly if you're doing a lot of planing for example. While the 6" cyclone can be mounted to any size container of your choosing.