Looking to upgrade any info would be a great help

I have Your answer alex

Yes that is amazing the larger the tank the better,because the water chemestry is way more stable than small 1's. rule is 2 gallons of water to 2 inches of fish. I have a 90 gallon fish tank with an eheim canister filter, under gravel evenflow filter with an 801 aquaclear power head plus another cartridge filter with another 801 aquaclear power head. all 3 of these cost a bit more when your fish will thenk you and you will be happy and feel great.
I have 2 oscars 1 pleco and 1 red devil their happy and healthy.

ps: Aqua-sol = prevents deseases use it and get a siphoning gravel
cleaning hose hooks up to your faucet its fast and easier to clean.
It's worth it you will see bud.

I hope I've been a help Alex. Mike

Upgrade info

If you are going for a planted tank then you will put a major investment into lighting.
Some suggest 2 to 3W per gallon ... so in your case 200W to 300W of light.

Get a cannister filter (as suggested by Mike). It is worth the money ... we converted our 38 and 75 gallon tanks to cannister and it has never been cleaner (and quieter).

Be very thoughtful about what fish you are going to put in it. Do not randomly buy fish. Do some research into their social interaction and group size.

I think a lot of how you proceed will depend upon how much you want to spend. At 100g you need to decide if you want to buy a predrilled tank. With a predrilled tank you can run a sump filter setup and most likely get your heater out of your tank and out of sight. Me personally I'd probably want a non drilled tank and run a combination of 2 filters. I'd probably go with a Fluval 405 cannister along with an AC 110. You can go with a single large cannister, but on a tank of that size I'd prefer 2 filters. As mentioned already lighting can be a concern on a tank of this size. If you want a planted tank your going to need a good load of lights. Again if it were me I'd be looking into a DIY hood and lighting set up. My thought on actual lighting would probably be a 4x55 watt cf setup from ahsupply for starters. That would put the tank at 220 watts of lighting with some good reflecters. If I find I need more there should still be plenty of room for another 2x55 watt cf at least. Now if your not looking into a planted tank I'd still go the DIY route, but instead of the cf lighting I'd look for a regular flourescent light from Home Depot. A simple 2 bulb kitchen fixture would probably give you enough light for basic viewing. A 4 bulb t-8 would probably look even better though. Also if you don't have a python or an equivelent it would be a good time to buy one along with an extended gravel tube.