Dell servers seemed, to me, to have had a better record of being fully supported, especially brand new ones at release date. R510? R710?
R710 is a good bet: http://www.nycbug.org/?NAV=dmesgd;f_dmesg=;f_bsd=;f_nick=;f_descr=poweredge;dmesgid=2016#2016R910 is more 'midrange' on Intel, now that I have perspective having been exposed to the IBM POWER platform, and should be the R710 with a lot more disk capacity.
Which you will pay for. Be prepared to make a tough call on r710 + SAN/DAS v.s r910. Your application and your CFO will dictate.
~BAS