Server/workstation boards don't have overclocking features at all since generally those processors are not unlocked; only a handful of X79's have single-CPU Xeon E5-1600 support, but those processors don't overclock.  Unless otherwise specified, many server/workstation boards don't support SLI, but they do support Crossfire.  This is legacy, back when ATI was an independent company and made a deal with Intel; while AMD now owns ATI, the deal is still in place on certain server/workstation boards.  Even EVGA's boards do support Crossfire, as a result of the legacy deal, but EVGA's exclusivity with nVidia prevents them from marketing it disrespectfully and blatantly , but you can find it in manuals.
 
You'd have to go to the manufacturer's website, hit up their support section, download and look through the board's manual to see what support is there-- this is the homework I recommend for you.
 
Mainstream boards are categorized as Intel H-series and may not have fully featured RAID support, if at all; that market of consumers typically wouldn't run as many drives in RAID anyway.  Their advantage is they are cheap and support any processor meant for them without hassle or tinkering, it just works.  Server/workstation boards also have the same quality, but are just expensive.
 
Thesedays, gaming and overclocking is treated as synonyms by enthusiasts (both Z-series and X-series Intel boards), as such motherboard manufacturers will attempt to blur the lines catering to just about every demand possible to net the most sales-- these are the types of boards you find in the $250+ category for single LGA1155 or LGA2011; EVGA's top model Z97 may be your ticket if you aren't looking anywhere else.   
 
Intel has had their own auto-overclocking feature called "TurboBoost" in all their processors (server/desktop/mobile) for several years, but they only engage when less cores are used, with the highest frequency when only 1-2 cores are active.  The i7-4790K has a boost to 4.4GHz from stock 4GHz, but it isn't for all cores. 
 
FYI, you can game on any CPU or GPU combination (but mainboard doesn't factor unless you want overclocking or multiple graphics cards); there are no application-specific components in the computer world unless we're talking about an embedded system like a console or smartphone.  Its the modular aspect of PC that makes it better, application specific is not modular.
 
The catch is your preferences; many members here like the highest details with the most fluid frame rates, thus only high-end qualifies (CPUs at $300+, boards at $250+ and graphics cards at $350+, etc).  They tend to forget that not everyone needs their preferences, thus they tend to belittle components like midrange or slower as "not meant for gaming", which is BS since nothing is built for one task anymore.