within uae have u considered janitor service. u can get experienced cleaners for some certain wage and make contract out to various offices etc.
if you are looking for investment without work or active involvement your return may be delayed and your investment would be at risk. i would also suggest to look into computer repair/software/hardware shop. but avoid pirated stuff otherwise ahem ahem
camel milk demand is increasing heavily in west you should look into that perhaps become its exporter. camel projects thriving in uae.
you can also look toward education sector and proivde some sort of technical qualifications by becoming a uk- affiliated institute for bodies like city and guilds or other technical bodies. education is estimated to grow heavily in uae. moreover u can also consider investing with franchise of pakistani school in uae as lot to be made in education.
in all things your pr wil matter have the friends with general trading license in uae. in recession period they lost almost everything move in small 2-3 room flat in sharjah. now back again. pr contacts helped a lot and ofcourse business decision. now they are mainly importing sugar and raw agricultural stuffs from brazil.
my one more friend in uae does work as: employment agent. he is taking from pak the people to uae. he has in short period Alhamdulillah received the contract for dubai airport porters. taking 10-15 people there. earning good return from airport and making contact along the way. he also have his brother as emmployee with one royal of uae so the contacts matter 
good luck to you.
BEFORE investing
1. charity sadqa. what you give will come back to you increased 20 times or more. make life easy for yourself and future generation donate the money. not my saying but promise of PROPHET SAW
- Istikhara