Lead
Groundon @Iron Ball
252 HP
252 Attack
4 Defense
Brave
Earthquake
Fling
Protect
Swords Dance/Rock Slide/Stone Edge
With lead
Cherrim@ Lum Berry
252 Sp.Defence
252 HP
4 Speed
Calm nature
Solar Beam
Protect
Helping Hand
Safeguard
Groundon is used as the obviouse lead to get sunny day out there, wich in turn activates FLower Gift. If an opponent is a TR then even better, if not Groundon will have Fling. Cherrim will be used with Aromatherapy/Protect/Leech Seed/Helping Hand or an attacking move. Don't bother with Aromatherapy, use Safeguard instead with Lum Berry attached. This way, if you encounter a choice scarf Smeargle, you can simply protect with Groudon and use Safeguard with Cherrim on turn 1. I would use Solar Beam over Leech Seed, because the battle won't last long enough for Leech Seed to really help.
(Question: Can a 252 Sp.Defence boosted by Flower Gift Groundon survive a 252 Sp.Attack full health Water Spout in Sunny Wheather?) Yes, it can. It doesn't even need 252 special defense EVs. I have seen Groudon survive max power Water Spouts in the sun before without any investment in special defense at all, and not even 252 HP EVs.
Ho-oh @Life Orb
252 Speed
252 Attack
4 HP
Adamant
Brave Bird
Sacred Fire
Earthquake
Protect
Ho-oh will come in as some one to Kick ass and take names aswell as one who will utilize Thunder Wave. Status moves are not very useful in this format, because they take too long to have any real use. Most battles will be over before 10 turns have gone by, so T-Wave and the like are not very useful. Only sleep is useful, in my opinion. I find Sacred Fire and Brave Bird to work well together as long as I carry recover. No, recover is a bad idea in this format. Your opponent will simply target Ho-Oh with both pokemon and you will die regardless of your recovery. Other wize Ho-oh would have to be used last in game and substiture Brave Bird with Sky Attack Never use Sky Attack, ever. It is like a worse version of Fly, which is still pretty terrible.
The last slot on the team is still up in the air, I'm split between a Bullet Punch/Exploding Metagross or Priority moves Scizor (may look like it doesnt belong in sunny wheather but it gives some sort of coverage and back up) Don't do this, you have 2 physical attackers already. Use a special attacker instead, as I outline below.