i have to make 100 cupcakes for a wedding coming up and i am going to be using the taller cupcake liners to make it look pretty 

the ones i use now are the stuff you get in the grocery store  by reynolds i use 1/4 cup but since i am going to be using taller size liners how much batter would you recommend i use i don't want my cupcakes overflowing 

 Every recipe is different, so I recommend that you experiment with a few batter amounts, to get the right height for your cupcakes. 

Do you use portion control scoops? Using these scoops makes it easier, more consistent, and controls cost.

You are currently using 4 tablespoons, which is 1/4 cup. That would be the blue disher/scoop #16. The next size would be green disher/scoop #12, at 1/3 cup (5.33 tablespoons). Here's a link to a chart. Good luck!

I use the hot boiling water recipes for both my chocolate and vanilla base. I just use a regular 1/4th measuring cup to portion out my batter.

do the scoops work better?

I use the "midi "size liners, bigger than a normal but smaller than a jumbo, and use 1 full ice cream scoop. They bake up perfect, just slightly above the top of the paper. 

And adjust you baking method to "dome" or not "dome" the tops. I like the "dome" effect so I baking accordingly to achieve that . A flat top cupcake, even with plenty of icing just looks "skimpy" and not "generous" to me.

How do I get them to dome

With most recipes, you initially put the pan in a hotter oven. That makes the outside cook faster and makes the batter rise and push outward to dome. For me, I start with an oven preheated to 355 degrees, pop the pan in quickly and bake 5 minutes and then reduce heat to 325 to finish. And I rush to get the pan into there ASAP so the heat doesn't escape.

You need to practice with your oven and your recipe.

If you want "flat tops", I go 325 all the way.

Since you are experimenting, I would set up a pan with liners and use different scoops to measure out each liner. Using a "disher" or portion scoop is a lifesaver. I have even used XXX disher plus an extra blob to "create my own size". JUST BE SURE THAT "extra" blob goes in FIRST, under the full portion or the tops will be wonky. Then bake it. Set up one pan for "normal" baking and one pan for high temp start. You should have a number of examples to see what look you like best, and snacks for friends and family...lol.