External Filter

The Fluval 106 comes with media. According to Hagen's website, it has biomax (a ceramic medium) a polishing pad and a bag of carbon. If I was to use this filter I would put the carbon in the cupboard, then buy some sponge, any make that can be cut to fit. The instructions say the media has to go in a certain order but I'd put the sponge in the bottom basket to catch the debris, biomax in the middle one then the polishing pad in the top one to catch any fine bits.
To preserve the bacteria you have grown. put the media from the internal into the external. You don't mention which model internal you have but with sponges it would be easiest to bury it in the biomas basket, and any biomax in the internal can go in there too. Once the tank is cycled, and has been running a few months you can remove the sponge bit by bit and replace it with the new biomax you'd have to leave out.

The Fluval 106 has an adjustable flow so it should be OK on a 60 litre tank, but nowhere in the instructions does it mention a spraybar. If any member has an x06 filter, they should be able to help with this.

... can you put more media in these external filters and what type also would I need a spray bar attachment ...

External filters generally have more space for filter material than internal filters.  You can put any filter material you desire into it.  You don't need a spray bar but I use them to break the surface film over a greater area.  This helps to oxygenate the tank.

Pros
More control over filter material.
More filter material than internal equivalent (good for seeding other tanks).
No filter in the tank so less interference with your aquascape.
They have an internal water capacity (i.e. my mini external holds 2.3 l, Fluval claims to hold more but gives no numbers) so increases the volume of water in your system.
Easier to clean.

Cons
Usually expensive.
On a small tank isn't as efficient a filter as a cheap sponge filter (but does the job still).
From observation, not used by many breeders who prefer a low flow.
Can block on larger bits (use a pre filter to remove this as an issue).

You'll need to research carefully about the diameter of the tubing for the external filter, including any fixtures and fittings which may create a problem when trying to shut the lid on your tank.

Can anyone recommend a quiet external filter, there are a lot of options on the web and pro's and con's to which brand. Looking for filter for 90 litres (maybe 120) havent committed to a tank yet.There's a lot of Experience on this forum and would appreciate any input,I'm thinking of an ehiem.

All Pond Solutions externals are well known for being good value for money, albeit a bit on the flimsy side But as long as you are aware of that and are gentle when cleaning them it isn't a problem.
The other thing with them you need to bear in mind is that they are one of the brands that quotes the flow rate of an empty filter. It is well known that once you put media inside, the flow rate drops substantially by anything up to half of the empty rate. So choose the model with this in mind.

Just had a look at the all pond,it seems to cheap to be true !
https://www.allpondsolutions.co.uk/aquarium/filters/external/ef-150-400-l-h/

Priming has been tricky after maintenance but it was eventually solved with an easy fix.  Stick some air tube down the in pipe and create a siphon to fill the pipe.