I will take a stab at this....
I am also a one man shop,
I have a sp300v roland printer,
I use primarily one brand of media,
sound ok so far?
I use to have oracal 3651, in stock and the 3951, in stock, one for the low end and one for the high end, over a period of time I found that it wasn't worth stocking two different type of media, I had some trouble with the oracal 3951,
and I stopped using it, then I switched to arlon
I use the dpf6000xrp with the matching lam, and this is all I use, it is cheaper than the oracal, and performs better, (this is my opinion) if I need to do a low end print I will print on 651 vinyl, or maybe 751, depending on what I need to do, or the particular job, I have found it way more cost effective to use one material than to stock many types,(the difference in cost between the materials per sqft is so minimal that it does not pay to stock so many types of material unless you are doing a high volume of cheap signs then it might pay off to have the cheaper material on hand which I can have in a few hours from my supplier) of coarse I have window pref on hand also..but you get the idea, after you get the printer and get familiar with it, all this will work it self out, but I mainly do trucks and vehicle stuff, along with higher quality signs, so the media I have chosen fits the realm, of most of my jobs,
I also believe that Geno is right, with what He is saying but he is running on a larger scale than I am or I intend on doing, and I think that is where the differences comes in, so it will depend on what you want or need to do,...
also don't forget that you will need a laminator to go with that printer...and don't cheap out on the laminator, if you do you will loose more money redoing prints .....now for the disclaimer this is my opinion which does not reflect signs 101's policies and or decisions...what the heck do I know I am just a sign painter,,,
//chopper