Guinea-pigs are fantastic little mammals , DD would agree that boars are more affectionate than sows .
I'll give you the down-sides ( too late as you've already got them
)
They need loads of space especially 2 boars .
They need protected against cold/heat/damp/draught/foxes/cats/birds of prey.
They are very untidy but the hay smells more than them . If guinea-pigs smell it's because their houses aren't clean
They are vunerable -don't really climb or shift themselves , unlike rabbits they don't have powerful kicking back legs They do have rodently teeth but they don't really bite (and if they do it's 99% handler error)
Make sure their accomodation is secure , outside I used rabbit runs pegged down with heavy duty tent pegs . Piggies don't dig but something else could dig in.
They do need a careful diet - unlimited hay , Vit C (in the pellets and veg) Not too much fruit , no ice berg lettuce , not too much dark green veg ( brocilli, kale , spinach- ) can give bladder stones .
They'll love peppers, celery leaves and stalk(but no strings) carrot, salad,(except iceberg) herbs , fresh grass, dandelions, bit of watermelon rind,
No potato , onions, bulbs, daisy, buttercups, fruits with stones . No fermented grass or lawnmower grass
They are noisy , chatty, greedy . Stomachs on legs .
Not nocturnal but crepuscular (dawn/dusk) . Indoors they think 3am is a good time to demand food ( I used to cover the cage like they were a parrot )
Boars can get a bit stroppy keep a close eye on them.
Give them lots to do , boxes with 2 doors so one cannot trap the other
2 water bottles and food bowls or make sure they cannot crowd the other out .
They hide illness very well , they're prey animals . Being ill means you are Dinner . So you will pick up on any illness if you watch them and get to know them .
Your rabbit vet should hopefully be savvy with piggies ( guineas are Exotic ) , they hopefully won;t need a vet but best be prepared .
Buy mite drops ( I used Zeno 450 online )
Don't put the piggies with the rabbits -a rabbit can kill a guinea-pig and they can carry a bacteria Bordetella bronchiseptica which can affect a piggies respiration.
And I say this with great love and affection for the Guinea-Pigs of the world - they are as Thick As Mince . But that's their charm.
Everything else about guinea pigs is good . Until they pop their clogs and break your heart .