>>Tire choices always seems to be overly confusing.

So what is a good tire to use with 15" rims?  I do not want to go to a larger diameter so 215/75x15 is out (my 1.9L motor works hard enough already).  Most of the 215/65x15 tires do not have a high enough load rating (tell me what tire has the correct rating if there is one).  205/65x15 tires have a smaller diameter than the stock 185R15 tire so the engine will rev higher.
I drive a two wheel drive Westfalia so the load carring capacity is important.  I drive in the mountains so I do not want to oversize the tires,  I am leaning toward the 205/65x15 tires but would like to find a set of 215/65x15 tires with the right load rating. 
I have a set of 15" Audi rims with machine work done and a set of spacers and longer bolts/studs ready to go.  I just need to find some tires.
Thanks for any help.
George
'85 Westfalia
PS  Does anyone know the revs/mile or kilometer for the four sizes mentioned. (185R14, 205/65x15, 215/65x15 and 215/75x15)