Ideal stats for a range tank are 99 range, 99 mage, 99 def, 99 hp, 75 attack, 75 strength. If you are a staker, then leave your summoning and prayer at 1, which would leave you maxed out at 98 combat. If you plan on pking or pvming, then just get 44 prayer and would make you 103 combat which is what I did on my range tank.
That would definitely be something to get eventually, but I would wait until the rest of your stats are maxed or close to it. If you plan on staking a lot, then you want to keep your prayer at 44. It's already hard enough to find fights when you're a maxed tank and having soul split makes it nearly impossible.