The Juwel Rekord 700 gives you an extra 5 litres volume, and also an extra 10cm length. The volume is so nearly the same as the first tank that the same stocking list will still apply.
Having has a Juwel Rio 125, you'll have virtually the same filter I had (mine was just an older version). According to Juwel's website, you filter will come with a blue sponge, a green sponge, a black sponge and a white pad.
The blue sponge is home to the filter bacteria. Ignore what they say about replacing it every few months, it only needs replacing when it goes into holes or won't go back so shape when you wash it by squeezing in old tank water (taken out at a water change)
The green sponge is supposed to contain bacteria to remove nitrate. It doesn't usually work. However, it is a perfectly good home for the filter bacteria so treat it like a blue sponge.
The black sponge contains carbon which you don't actually need to run full time. Carbon is only used for removing medication after treatment has finished if the fish get sick and for removing the brown that comes out of bogwood. Leave this in the cupboard in case you ever need it. Either replace it worth more sponge, cut to fit, or in the short term seed the tank by putting some media from your other tank(s) in its place.
The white pad catches bits of debria and will need changing regularly as it will get clogged. It won't grow many bacteria during the time it is in the tank - and it isn't a particularly good home for them anyway. But don't spend money on Juwel pads; get a roll of filter wool and use a pad as a template to cut the roll up.
Have you found the Community Creator yet? It's accessed through any fish profile in the menu bar at the top, right down at the bottom of the profile. You can save what you enter but you have to register and log in separately from the forum. And it does have a habit of logging you out if like me you take ages looking a different fish before entering any!
Besides the fish profiles on here, another good site for researching fish is
Seriously Fish which does have more species than here.
You have a while during cycling to decide what to get