I'm thinking of giving Gold Tips a try.

Present setup is a BW PSAX  50# @ 29 inches.  I shoot a 30 inch arrow.  2117's with a 125 gr tip work well.  So do 2216's cut to the same length.  2020's are too limber.  

Now, armed with that info.....the Goldtip websight says I should shoot 5575's with my weight and draw length.  As I tend to require arrows a bit on the stiff side (probably a form issue...don't go there) my fear is getting 5575's and them not being stiff enough.

Any input would be greatly appreciated.

I think they should be plenty stiff.  I'm shooting 66# @ 28inches. My 55/75's are cut at 29 1/4" with 160 gr. heads.

If ya shoot the 55/75s even at 30"s ya will have to add quite a bit of point weight. I used to shoot them out of a 62# SA and cut them to 29"s and needed 225 up front for perfect flight. I would think ya need at around 275 up front for good flight and maybe 31"s long. I think the 35/55 with 175 up front would work well cut to 30"s. Shawn

Shawn is right
a 50# will shoot a 35/55 at 30" standard insert and about 150grains up front pretty well, 55/75 you will need more weight up front, Iam shooting 55/75 out of a 56# bow, 29" with 200grains up front.
Get the test kit from 3 rivers and then you will know for sure.

I'm basically shooting the same set-up(bow & poundage) as you Otto & the 35/55 with 100 grain brass insert with a 125 tip shoot real well for me....55/75 were a little to stiff.