I know Detox for Less is the site sponsor but in your guys opinions which is the best place to order from to get Quickfix, also which is better to have the regular 2oz size or the 3oz.
Both the 2 oz and 3 oz are winners, however, 2 oz is enough for a sample. The collector may ask for more, only to discard the excess. Under DHHS regulations, if 2 oz is all the donor can submit, the collector has to accept the sample.

1. B2 or B12, I have both so I just plan on taking both and seeing what happens.
The proper vitamin for urine color is B2 (Riboflavin). But keep in mind that with creatinine and S/G checks having become lab SOP in recent years, color became the least aspect in determining an overly-diluted sample. Even samples with a nice yellow color to them can still register unsatisfactory S/G and creatinine levels.

2. Creatine - I purchased Amplified Creatine 189 is this the right stuff? Each serving I guess is 1250 mg, how much should I take
If its creatine-monohydrate, then youre good. Just be sure to do your creatine-loading 3 days prior to the scheduled U/A to allow the necessary time for the body to metabolize creatine into creatinine (the end waste product that is present in the urine and tested at the labs).

As far as doseage goes, that would all depend on what your "baseline" creatinine level was before your dilution practice drill - and you will not know this without performing your own creatinine and S/G tests with a validity test strip.

High creatinine levels are a non-issue because there are no upper limits established for creatinine. Under DHHS regulations, as long as the creatinine level is over 20 mg/dL, its satisfactory.
However, this does not mean that you should go crazy with creatine-loading. Going overboard on creatine supps can result in long unwanted bathroom sessions, sitting on the toilet seat

For subbing: Using the urinator I planned on putting it between my legs is there a better way to hide it?
Artificial delivery systems such as the Urinator are not necessary unless you will be watched (employment-related U/As are not observed unless you had been suspected of tampering). And even in observed situations, the use of such systems is very iffy and therefore not recommended. Observers, following the regulations outlined by the DHHS, are to be inside the stall with the donor and directly watch the flow of urine exit the body and into the specimen container.

Follow the hiding tips outlined in N2's Substitution "sticky" thread and PRACTICE.