A drilled tank makes things a little more trouble free. Many here are not using drilled tanks (I have both drilled and not drilled) The main issue with a non-drilled tank is that you have to use a HOB (hang on back) overflow. Since it's exposed to light it needs to be cleabed regulary (monthly at least) and there is a chance of loss of siphion and that will cause a flood basically the water in the tank stops draining and the water in the sump is still being pumped into the tank and what ever does not fit will end up on the floor

But a watchfull eye and some cleaning diligance can keep this from happening.
I would suggest you consider al your option before buying any new equipment. Consider what you want to keep and the requirements of each type of coral. The only equipment that will vary depending on what you keep is lighting and flow. The things you will need no mater that you chose are a quality skimmer, more live rock (probally 100# total min). The LR and skimmer are all the filtration you need. If you want to keep a mixed reef you could take out the media from your canister filters and run carbon in them.
Overflow and sump. In a 110 you will probally want a overflow that will handle up to 1000gph. I think CPR makes a good one but you can find cheaper ones. For a sump put the largest rubbermaid that you can fit under the tank. Or find a good size old tank. I use a old 35g under my 75. The get yourself a reliable return pump. Make sure if you get a insump skimmer it will fit in the sump and under the tank. I messed up and got a skimmer 1" taller the underneath my stand and now it sits next to the tank
as for skimmers I like getting one reated for atleast 1-1/2 times you volume. there are too many makes models and styles to get into that now.
Be wary of LFS advide. He/she is already trying to get you to buy a new Reef ready tank that you really do not need. most are out ot make a buck. Some are great and helpfull. but never take there word for it unless you really trust them..
Oh and you should probally beef up our clean up crew a bit.
I suggest around 30 snails and 50+ hermits I also like to keep a emerald green crab or two to keep
bubble algea at bay

(everyone has a different take on cleaner crews)
Before you make any changes carefully consider all your options. make a plan and follow it the best you can. Ask lots of questions here and take all the advice and do what works best for you. you may get som conflicting advice hree as there are thousands of members and all their tank are different. take all the advice and use what you think will work for you. Or at lease the most common suggestions. Do it slowly there can be a huge learning curve in reefkeeping and it's usually costly and can hurt. Buy in the end after a little time it will be very rewarding!

Good luck and keep us posted and keep thise questions comming...