Changing font size at text block

Dear Sir,

I progress very well with HighEnd theme !!! My page is a Block Text similar to:
Line 1
abcd abcd abcd
Line 2
xyz xyz xyz
Line 3
ab12345 v ab12345 ab12345
I would like to change font size at any specific place,for example: Line 1(size 72)
and for another example: Line 2 (size 36),and for another example: Line 3 (size 18) etc ,etc ,etc
The Heading options will aloud me to have 6 different options and I know how use it.
Is there any plugin like “Black Studio TinyMCE Widget” (not confidence this is the accurate one for this porpuse) that will aloud me font size changes simple and easy.
The best for me if this plugin adds an icon to any page (like Color Font,Bold,Align Center and others controls I have in each page), Thank you , Best regards,Haim