Hi and welcome!
It is great that you are doing your research beforehand!
On principle, the more space you can offer your guinea pigs the better; it should comply at least with minimal welfare recommendations (which your planned cage does) but whatever you can afford to go above is a bonus.
However, this depends very much on your individual possibilities. Supervised daily run and enrichment time is perfectly fine; piggies are most active in the mornings and late afternoon evenings and tend to sleep a lot during the middle of the day. If you have the space and means to have a run attached to the cage that is accessible all day, then that would be great; but it is not a must!
While we all strive to do our best for our pets, there are some people out there who have sadly become apostles for standards that are for most owners simply unrealistic and not practicable/affordable. Pet ownership should not become just the privilege of the few rich as long as a reasonable standard of care can be provided - which you are planning for.
Energetic youngsters and teenagers (especially boars during that time) need the most space and exercise time; adult run time very often consists of a 5 minute amble around the area and follwed by a nap in their favourite corner!
Cage Size Guide
Enrichment Ideas for Guinea Pigs
If at all possible, I would recommend to consider adopting from a good standard rescue if you can get to one for a problem-free start into your piggy life. Any piggies you adopt will be carefully bonded as to character compatibility; they will be fully quarantined/medically cared for and healthy when put up for adoption, properly sexed and guaranteed not pregnant. You will also always have the rescue to fall back on if you run into serious trouble along the line. The rescue will also match you up with piggies that are suitable for a new owner and that are used to human interaction and being handled, unlike pet shop or breeder piggies. A good standard rescue is by far the best and safest place to get guinea pigs from.
If you want to go down that route, then asking the rescue for their recommendations in respect of cage size/indoors and outdoors runs would be best.
Boars, sows or mixed pairs; babies or adults?
Recommended and vetted UK rescues:
Recommended Guinea Pig Rescues
Recommended and vetted rescues in some other countries:
Guinea Lynx :: Rescue Organizations
Please note that these are the rescues we can vouch for that you are in safe hands and that they uphold welfare and good practice at all stages of the rescue process. Sadly in English speaking countries, anybody can call themselves a rescue or a breeder without licensing or welfare checks, and the results can be accordingly.
You may find the information in these two access links helpful for your further research:
Are Guinea Pigs For Me? - A Guide
Getting Started - New Owners' Most Helpful Guides