Yeah it's got me paranoid now, because sometimes I use Mflash, tonight I decided to use the MSI forum flash program.
Was it the MPower you had or the XPower, because the BIOS downloads you linked were for the MPower, latest one being 1.5, XPower only goes upto 1.4
As for motherboards, if your just gaming - a cheap <£130> will do everything you need, but if you want the extra features that come at a premium go for it. The Asus Z97 Formula is a nice board.
Just make sure you buy it from Overclockers because Asus are crap with RMA - even with OcUK your looking at 28 days, longer with other retailers.
I've got a 4790K, I've been considering the Asus Maximus VII Ranger, but I like quick RMA turnaround so still unsure yet.