I really think having a 100GPD membrane is overkill for most people, especially since the 100GPD membrane has a lower reject rate (so your DI resin will exhaust faster) and it's easy to make the water up ahead of time anyway, negating the need for the additional 25GPD output.
I agree with the recommended vendors being AWI, Buckeye, TFG and Spectrapure. I personally have the AWI Typhoon Extreme and highly recommend both it and the company. The unit works great and at a reasonable price (not bargain basement, but very reasonable for the features and quality). Most important though, AWI offers a lifetime warrenty on their products and they stand behind that warrenty. I've had a booster pump and a couple of other parts replaced over the years with no questions asked. They even replaced my ASOV twice in a row before we figured out that the issue was headspace on my part, I had left the DI bypass partially open, and they did not ask for payment or return of the ASOVs.