if the gas block on your varminter is the same as the one shown
here then thats bushmaster's low profile gas block/filed down fsb.
now if thats the case the front sight you need that would not require you to do much work other than clamping it on is
this one which is also available from bushmaster themselves.
all of their b.m.a.s. product line is yankee hill manufacture so what i would do is get the part # and look for brightflashlights in the industry forum and send him an email/im and see what he can do for you.
great guy to deal with and has pretty good prices to boot.
but if you want a totally different front sight then what you can do is buy a front flip sight like the pri,yhm or what ever and install it yourself or send to someone. most require removal of the gas block you have on there which could become more trouble than it's worth cause the pins sometimes dont wanna come out.
as for the rear sight you would need to get some sort of flip sight so that it would fold away under your scope.
be sure that whichever one you choose it is low enough to fold underneath the bell of the eye piece.
either the troy, arms #40l come to mind
some sort of quick detach rings(arms or larue) would help in quick removal of your scope so that irons could be accessed.
i would not try and raise the scope high enough so that the irons are able to be used cause that would greatly effect the cheek weld when using the optic. if you have flip/folding sights you wont need to do this.