If all you want to do is have the input of a simple form sent to you by email, then Contact Form Solution Pack should be fine.
There is more functionality are more options with UE (and easier validation with CSSFormBuilder) - I find it takes quite a bit of fiddling with the design to get it to fit well with your page design with CSSFB, but the next version is promised to be more elegant with less convoluted css and markup.
How can we help with your CFSP contactus.php form? What happens (or doesn't) when you upload it to your server, fill in some fields and press the send button. Does it send - do you get to the thankyou.php page?
If you could provide a link to the page online where we can see it, and perhaps zip and upload your form page as an attachment here, we would have something to go on.
Check that the entire contents (files and folders) of the downloaded ContactForm_GMC have been uploaded into the same folder on your remote server, and that you have entered the correct details in to the WA_Globals.php file.
The important lines to fill in in the globals file are:
$WAGLOBAL_Email_Server = "" ;
$WAGLOBAL_Contact_Email_To = "firstname.lastname@example.org" ;
Most often the Email_Server can be left blank, but make sure you have the recipient's address correct in the Contact_Email_To line.
Put it up 'as is' to check functionality, and if you want help integrating it in to one of your existing site pages after that, the we can help with that.