I would vaccinate against Marek's, the coccidiosis vaccine comes down to personal choice but I lean towards no on that one. If you do vaccinate against coccidiosis, don't feed medicated as it'll negate the vaccine. Honestly, you don't need to feed medicated either way, the medication in the feed can help if they get sick but you'll still need to give them corid if they get sick. Honestly the whole medicated vs unmediated feed thing is a hotly debated topic in of itself, just don't give it to them if vaccinated against coccidiosis, and it doesn't matter much otherwise, just keep keep the brooder clean and dry and corrid on hand and they should be fine regardless.
Other diseases it depends on what diseases are in your area. What you vaccinate for in your area will be different from what I vaccinate for. I'd just ask other chicken keepers in your area have been dealing with