Bro, If you have been using 10w-40 instead of Toyota standard that recommended oil grade is 10w-30, it is even better, however, if you wanna switch to 10w-30 as per Toyota Standard, still no problem.
I think. you can use any of these oil grades; and in my opinion, you will not face any problem, even if you continue using 10w-40.
I would recommend following oils:
10w-30:
Havoline Formula SAE 10W-30 ( http://pakistan.chevronlubricants.com/en_PK/products/passenger-vehicles/passenger-car-motor-oils.html )
Mobil Super™ 1000 10W-30 ( http://www.mal-eshop.com/mobil1.php?mid=122 )
10w-40 (Preferable, and you may continue using this grade):
ENEOS 10W40 SN/CF ( http://www.eneos.pk/eneos-10w40-sncf/ )
Total Quartz 5000 ( http://totalparco.com.pk/individuals/our-fuels-lubricants/lubricants/products/#product-container )
ZIC X7 10W-40 (A) ( http://zicoil.pk/product/zic-x7-10w-40-vhvi-tech/ )
Mobil Super™ 2000 X2 10W-40 ( http://www.mal-eshop.com/mobil1.php?mid=3 )
The above links are just for reference only. You should only buy from the store you trust!
I hope, it helps. Thank you.