Dear friend
first of all, Shimshal Pass is no easy trek. it will test u and will test u in a tough manner. So i advise u to refrain from it. But if u are so determined to do this trek, then i advise that dont join any group or any tour operator.
Just go to Gilgit by whatever mode of transport u like. From Gilgit, go to Passu. From there get some guide and leave for Shimshal village using normal public transport (likely a jeep type vehicle plying once in a day). Ur guide will also guide u if u need to take porter or donkey etc for luggage carrying.
If u are lucky enough, u may find few more ppl going to Shimshal Pass. U may join them if possible, otherwise do it alone.
Almost 10 years ago, i went till Shimshal Village. On our return, we met a single girl (probably from Poland) with a guide and donkey. She told she is going to Shimshal Pass. Woh akele ja sakti hai to aap bhi ja sakte hain.
It would cost u much much less (may be in 25k-35k range).
Besides Shimshal, there are many smaller treks around Hunza, like
Rush Lake (most recommended)
Rakaposhi Base Camp
Patundas Meadows
Daintar Pass
Even Naltar Pass or Pakhora Pass are good enough treks.
