I have no idea on how high in level can Forochel possibly bring me to but that is just one of my concern. On whatever level high that is, what is the best quest pack that I should get next based on finishing Forochel with that questionable level? I really need responses based on experience on this since I haven't really started my newly bought Forochel quest pack and I'm trying to catch up with the ongoing sale. Thank you!
You don't mention what level you're currently at, but Forochel had enough quests for me to comfortably level a character from 45 to nearly 50. I completed nearly every quest in the region. As a VIP player, I also had some enhanced (double) XP for creature kills, so your mileage may vary.
After that, I was able to complete Volume II, Book 1 of the epic quest for my legendary items and enter Moria at level 50. (If you want a real challenge, you can actually do that epic quest first at level 45.)
Edit: Note that Moria (the only region intended to level from 50 to 60) does not appear to be included in the upcoming 50% off sale.