opinion on what to buy next

[tashpop]

i know these questions are usually asked by beginners and or youngsters most of the time, but i'm really torn here.

a quick run down. i have a gst for myself, its very powerful. i have also a losi after shock that i put together for my daughter, its really slow. and i have a almost brand new hyper mini ste with no speed controller.

most my hobby money comes from limited resorces and alot from wheeling and dealing. i have some funds now but i don't know where i want to spend it.

my options are:
i need a new better radio for my truck

my daughters truck is slow and we want to fix that
(currently i have a new 4s pack on its way)
i don't know if i should upgrade the esc to handle more voltage, or get a higher kv motor?

current motors i have are a 1380kv 6pole and a 1200kv kb45xl.
current esc is the infinate 160amp version.

my options here are to spend money on a higher kv motor then i have more motors laying around but should cost less, but i have batteries that will work with this, or i've been thinking about trying out the infinite 1/5 scale esc which handles 10s.

if i go with the new esc, only battery options i have on hand are 2 2500mah 20c 4s packs. i could go 8s1p on them but their power output is limited and i would need to order some batteries in the near future, but i could then move my current esc into the hyper ste and have a third running rc.

sorry if its long winded, but throw me your opinion if you would.