It's by no means gimped...far from it.
Builds for ?/cold are very hard to make and really depends on playstyle and how you wish to play it.
Basically every power in /cold are great and because of that it's very hard to make it all fit in there.
So? what's your plans? Solo? Teams? PvE? PvP? Hybrid?
Personally have a lvl 39 ice/cold which is built primarily as a buffer for PvP so that means he only has 2 attacks and Aim from the primary and every power from the secondary.
SingStar:
"Extremists LOVE to fish to get us annoyed so we break the forum rules."
CRACK68:
"The origin of life wasn't planned either, should all life be declared a bug and wiped out?"
Lionsbane:
"You know me.Ever the realist"
My mate is leveling an Energy/Cold as is only taking Energy Blast, Power burst, Aim and Nova. Not really worth taking anything else except maybe the snipe if thats your thing 
Havent had much experience of Cold but you could do worse than take all the powers at a guess 
thePhilosopher Martial Arts/Regen/Fire Scrapper
theRegulator Empathy/Energy/Soul Defender
Total Inertia Ice Blast/Kinetics/Psy Corruptor
Total Inferno Ice Blast/Thermal/Leviathan Corruptor
This alt with be a team alt and therefore i will loom to the cold powers with enough energy attacks to add a little damage.
Altitus doesnt have a cure just more alts
Cold is a team set...that's how it is.
My ice/cold is atm lvl 39 but below is my 50 build. I've tried various builds where some where more solo friendly but have ended up with the below. This can still be used for soloing...a bit slow though.
Name: Arch Fahrenheit
Level: 50
Archetype: Corruptor
Primary: Ice Blast
Secondary: Cold Domination
---------------------------------------------
01) --> Ice Blast==> Acc(1) Acc(15) Dmg(17) Dmg(17) Dmg(25) Rechg(31)
01) --> Infrigidate==> Acc(1) Acc(9) Rechg(9) Rechg(13) Rechg(13) DefDeBuf(15)
02) --> Ice Shield==> DefBuf(2) DefBuf(3) DefBuf(3) DmgRes(37)
04) --> Snow Storm==> EndRdx(4) EndRdx(5) EndRdx(5) Slow(46) Rechg(46)
06) --> Aim==> Rechg(6) Rechg(7) Rechg(7) TH_Buf(37) TH_Buf(45) TH_Buf(46)
08) --> Hurdle==> Jump(8) Jump(43)
10) --> Glacial Shield==> DefBuf(10) DefBuf(11) DefBuf(11)
12) --> Combat Jumping==> Jump(12) Jump(43)
14) --> Super Jump==> Jump(14)
16) --> Swift==> Run(16) Run(45)
18) --> Bitter Ice Blast==> Acc(18) Acc(19) Dmg(19) Dmg(21) Dmg(21) Rechg(23)
20) --> Stamina==> EndMod(20) EndMod(33) EndMod(33)
22) --> Acrobatics==> EndRdx(22) EndRdx(23)
24) --> Frostwork==> Heal(24) Heal(25) Rechg(36) Rechg(37) Rechg(40)
26) --> Hasten==> Rechg(26) Rechg(27) Rechg(27)
28) --> Benumb==> Acc(28) Acc(29) Rechg(29) Rechg(31) Rechg(31)
30) --> Super Speed==> Run(30) EndRdx(45)
32) --> Arctic Fog==> EndRdx(32) EndRdx(33) DmgRes(34) DmgRes(34) DmgRes(34)
35) --> Sleet==> Rechg(35) Rechg(36) EndRdx(36)
38) --> Heat Loss==> Acc(38) Rechg(39) Rechg(39) Rechg(39) EndMod(40) EndMod(40)
41) --> Charged Armor==> EndRdx(41) EndRdx(42) DmgRes(42) DmgRes(42) DmgRes(43)
44) --> Aid Other==> Heal(44)
47) --> Aid Self==> Heal(47) Heal(48) Heal(48) Rechg(48) Rechg(50) IntRdx(50)
49) --> Power Sink==> Rechg(49) Rechg(50)
---------------------------------------------
01) --> Sprint==> Empty(1)
01) --> Brawl==> Empty(1)
01) --> Scourge==> Empty(1)
02) --> Rest==> Empty(2)
---------------------------------------------
Can't comment much on the nrg side.
SingStar:
"Extremists LOVE to fish to get us annoyed so we break the forum rules."
CRACK68:
"The origin of life wasn't planned either, should all life be declared a bug and wiped out?"
Lionsbane:
"You know me.Ever the realist"
I have just started an energy/cold corruptor and noticed a lack of guides for this build. Is this an oversite or is this build 'gimped'?
So far have ice shield, infrigerate and power blast. Are there any must have / dont take powers in these sets?
Altitus doesnt have a cure just more alts