Stepping into AG with 2 or 3vessel brewery?

Hello All,
I am going to finally take the plunge into AG. I recently built a house and had a Natural Gas hook up installed in the garage along with a GFCI outlet nearby. I need some advise on how to set up my brewing station. Here's what I currently have:

-20 gallon brew kettle with Thermometer and Ball Valve (thanks to my beautiful wife) :rockin:
-10 gallon circular cooler with ball valve and braided screen installed
-5 gallon stainless steel brew kettle, no thermometer or ball valve (my old extract kettle I used for 3 gallon full boil batches - not really a part of this system, but who knows)
-7.5 gallon aluminum turkey fryer with ball valve (never used for brewing)
-25' copper wort chiller
-water spigot in the garage
-an uncle who has a bunch of angle iron and is willing to weld anything I need as long as he gets to drink whatever he wants whenever he comes over.

I am planning on purchasing the following:

-a natural gas burner (or two?)
-a stainless steel pump (chugger from morebeer- any thoughts?)
-shirron plate chiller
-whatever connectors and hoses needed to connect all of this

So I don't know if I should set this up as a 2 vessel or a 3 vessel system. My original thought is a 2 vessel with the cooler up top and the brew kettle below. I can use the brew kettle to heat the strike water, then pump in for mash. Gravity will allow liquid to flow from cooler back to brew kettle. Then gravity from brew kettle through plate chiller to carboy. I've heard that allowing gravity to control flow through plate chiller is better than pumping through plate chiller. My cooler would be up pretty high so the brew kettle is high enough to allow gravity to pull liquid through chiller into carboy.

My other thought is using the 7.5 gallon aluminum turkey fryer for sparge water and strike water. Then the brew kettle just for boil.

My questions are:
1. Sparge (3 vessel) or no sparge? Why?
2. Is a 7.5 gallon turkey fryer large enough to handle the strike water and sparge water? I plan on brewing as large of batches as I can fit into the 10 gallon mash tun (so 5-7 gallons?).
3. With the pump and some quick disconnects is it conceivable to use the pump for the strike water and the sparge and perhaps even from kettle to chiller to carboy? Would it need to be sanitized after sparge and before transferring wort to carboy?
4. Any other ideas, links to set ups, suggestion?

I use a 17(ish) gallon cooler for mash tun and 15.5 gallon keggle in a 2 vessel system, so the keggle is heating my strike/sparge water and then I boil in it. I batch sparge. I collect my wort in buckets to keep my keggle free for sparge water, then I transfer to start the boil. I have just the one burner. I see no reason this wouldn't work fine in your situation with the bigger pot taking the place of the keggle. I can do 10 gallon batches easily with my setup. Also, if you're only doing 5-7 gallons you could definitely use the turkey fryer for strike/sparge. You just may have to refill for the sparge water. So you could do 3 vessels I would think, no problem. I use gravity for everything so I can't comment on the pump question with any real knowledge. Good luck, sounds like a nice setup!