In reply to Removed UserBoingBoing:
If you're just wanting to get to the summit by the 'Voie Normale' ( as far as Vignemale is concerned) the 'Bureau des Guides' at Cauterets will be your best best :
http://www.guides-cauterets.com/activites-ete/
A group ascension ( between 6/8 persons) will set you back 90€. I've crossed English clients on the mountain with a French guide who spoke pretty good English.
If you fancy something a bit more difficult, like the Face Nord, count on spending 500€. You couldn't do better than in the company of Remi Thivel :
https://www.remi-thivel.com/ascensionfacenordclassiquevignemale.html
For Aneto I'd contact the Tourist Office in Benasque :
http://turismobenasque.com