Advice Please External Filter For Trigon 190 And Moving To Set Up

I've had a quick look at the aquarium online because I'm not familiar with this one and the fit of the lid can be a limiting factor when considering an external filter.
From the pictures & descriptions I could find it appears that the tank comes with an internal filter and it has a flat fitting lid.
Are there any gaps towards the back of the lid where hoses could be fitted? Or are the gaps only large enough for the cables of an internal filter & heater?
Are there any holes in the back of the cabinet that hoses could go through to go on to a filter housed in the cabinet?
I have a few Fluval Roma tanks, and the lids are not really designed for external filter hoses either. Putting hoses through the gaps means the lid won't sit flat, unless you are prepared to try to carve some larger holes.

As for external filters for that size of tank, I've used the Fluval 307 on a 200L tank. It is quite easy to set up & use, but for your lid the hoses would be a bit of a problem.
I've also used the Aquamanta 300, which feels a bit less sturdy (but has never caused any problems) and the button/pump to start the filter can be a bit stiff. It uses thinner hose, so may be easier to fit in a tank designed for an internal filter, but I couldn't lay the lid of the Roma completely flat when using any external filter.

Hopefully one of the others will have experience with your exact model of aquarium and will be able to give more specific advice.