There are 3 ways to go at it when it comes to stats.You can either crit stack(20 crit on all yellow,12 sp 10 crit on red,12 sp 10 spirit on blue).With this you gonna lack a fair bit of sp on end-game but you gonna have more crit resulting statistically in more Hot Streak procs.
Or you can go with sth I find to be far better.Reds are 23 sp and if a socket bonus is below 5 sp,don't gem it properly,just insert 23 sp,yellow-12 sp 12 crit,blue 12 sp 10 spirit.
As for gear,spirit gear is not bad,escpecially f you have no other,hwoever,on BiS gear you will not have a single spirit item,and now since old molten/new warmane decided to ''fix''(it was not a bug) the T9 2p bonus having spirit items when you're high gear is even less usefull
Let me explain how this works and what people did sometimes for more crit.2p T9 gave you 15% more spirit converted into crit rating on molten armor,more mana regen on mage armor and more armor on frost/ice armor.The thing is you could swap pieces of T10 with T9,cast molten armor,then put T10 back and the extra % crit remained(it was ~1-2% usually,not bad for a fire mage).Now it does not work,so you don't really have to bother bringing T9 gear with you.Some mages really liked to go with say festergut 25hc belt and wand from vdw when this was around,but now that way of playing will be even worse.
Your BiS gears are as follows:
Head:T10
Neck:Chocker
Shoulder:T10
Chest:T10
Back:RS 25hc
Wrist:RS 25hc
Hands:T10
Belt:Marrowgar 25hc
Legs:T10
Boots:Festergut 25hc
Ring:Loop of the endless labyrinth(hc)
Ring:Ashen band of bla bla bla
Trinket:Charred twilight scale
Trinket:Phylactery of the nameless lich
Weapon:LK 25hc
OH: BPC 25hc
wand:Rotface 25hc
The % in hit ,you have 3% from frost talants.If you're alliance and want to capitalize on more sp/crit or w/e you'll have 1 % from dranei and boomkins,spriests and 1 more class i think give you another 3%.So you have 7% from outside sources.The spell hit cap is exactly 17%(note this is for your hit cap,not your images,your images will always have misses).So if you're alliance you'll need 10% hit,if you're horde you'll need 11%(this is of course if you want to maximize,if not just go 11% and you'll not have issues with hit)
As for how your stats will look like,while i had my mage I had
3376 SP
53,32% crit(with T9 thing)
32,54% haste = 1067 haste rating
10,41% hit from items