Blue
Ravenous Bugblatter Beast of Traal
Bladesinger is a no go because it forces you to be an elf and it's basically a wizard that can do a melee dance a couple times a day. Warlocks are too squishy to be fully melee capable, and what blaster cleric are you referring to? War/Tempest domain?
I understand a 50/50 mix isnt going to blast like a dedicated evoker wizard or sorcerer or warlock, but if he can attain half that capability, i'd be happy.
[MENTION=6787650]Hemlock[/MENTION] talked a little about Warlock getting fixed by starting with a level of fighter, and that can cure a lot of issues. Heck a Fighter 1/Abjurer X has great defenses and almost full casting, with spells known to match spell levels. But with only one attack they are hard doing melee, though the SCAG cantrips help level that playing field.
Full casters that can get Extra Attack or the equivalent are Warlock (Blade), Bard (Valor) and Wizard (Bladesinger). Amusingly you don't even need to be in bladesong use the wizard extra attack - with a level of something for heavy armor you could ignore bladesong all together, though that's giving up much of what that class brings. As a side note "melee dance a couple of times per day" is "melee dance all or most of the day if the DM is following the 6-8 encounters a day with 2 short rests about 1/3 and 2/3 of the way though". Though in my experience we have less than 6 encounters a day, making it even more likely to be all of them. Sorry elf/half-elf is a non-starter for you.
Tempest and Light with their spells added are the biggest blaster in the core books. Though Light doesn't get the extra weapon/armor profs, but still has medium and shields which is pretty good.
As a side note, with the advent of the SCAG cantrips, have you thought about a Mountain Dwarf Abjurer? You'll have proficiency with a number of martial axes and hammers, medium armor (no shields, but 2-handed weapons are better so you don't need warcaster), and full wizard (or whatever) casting. Extra attack isn't compatible with the SCAG cantrips anyhow. You'll have Shield, Absorb Elements and your Arcane Ward feature for defense from level 1 without using an action to cast or taking your concentration which you can use for a buff like Haste. That could give you plenty of blasting.