SDS or phono stage


I have a VPI Scoutmaster with Soundsmith Zephyr Mk II cartridge, jmw memorial arm, a stainless steel vpi record clamp, playing through a Musial Fidelity KW500 integrated amp with on board phono stage. Sounds quite good, but my question is this: would I be better off at this point adding an SDS or an outboard phono stage? Or both? In what order? Thanks!
arsh
I find the strobe disk a little hard to read with my old eyes. Using a digital tack from Amazon for only $16.00 makes it easy for the fine adjustments that the SDS is capable of.
This is the LASER tach that I chose: (http://www.amazon.com/Industrial-Grade-5URH0-Contact-Tachometer/dp/B004ZRN7AE/ref=sr_1_fkmr1_1?ie=UTF8&qid=1393294097&sr=8-1-fkmr1&keywords=5urh0+uni-t) There are many cheaper: (http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=laser+tach+uni-t&rh=i%3Aaps%2Ck%3Alaser+tach+uni-t) I also confirm my adjustments/speeds with the SDS strobe disk.