The best program to create them would seldom be Photoshop in my opinion.
I can’t recommend any shops, but as so often the things somebody knows, but doesn’t tell, may be significant – like how many different cards and at which numbers each?
And what paper etc.did you have in mind?
Any special requests like imprints etc.?
Make sure you have a .125 inch bleed on all four sides.
A normal business card in the US is 3.5 x 2 inches. With the bleed the document would be 3.75 x 2.25 inches.
But make sure that all image/text elements is at least .125 inside the trim size of 3.5 x 2.
So the safe area is 3.25 x 1.75 inches
Trim size is 3.5 x 2 inches
Bleed size is 3.75 x 2.25 inches.
All images should be approx 240 - 300 ppi or in vector format.
Just create 1 copy of each card with the bleed, the printer will do the imposition to best suit their printing process.
Even if a printer accepts PDF you can't assume that they won't open it in Photoshop and end up rasterizing all the text!
You can ask if they do this but don't expect to get a clear answer when dealing with internet printers. So be warned.
100 is a small amount for an internet printer, they usually start at 500, but usually 1,000 may only cost 1 or 2 dollars more.
Oh, and InDesign is the best way to go when creating business cards.
I am more asking for suggestion on companies to look into for a supplier
Here in the States I can recommend GotPrint, I had my own cards printed there, double-sided/glossy, they did a great job at a reasonable price!
On your card you have reversed text (white text on colored background).
Thin versions of fonts run the possibility of getting slightly filled in by ink from the background when printing.
Also, a "rich black" background will make this problem worse.
It is best to stick with thicker typefaces rather than thin or light typefaces to reduce this issue.
However,solid black text on a white background won't have this problem even with thin fonts.
Colored text will need to be thicker/larger since it would be printed with CMYK rather than black alone.
Gray text (a tint of black) will also need to be thicker/larger.
In the past, GotPrint has definitely rasterized some PDFs for business cards. They may not do this anymore or it may depend on the item ordered.
Recent postcards that I ordered did not have the text issue that I saw on earlier business cards.
However, even thought I noticed the issue, I think the average person is less likely to notice it.
GotPrint has a much better user interface than a lot of other printers.
I just checked and it now appears you can order just 100 cards.
I don't know where in the States you are but printing.com would be a good shout. http://us.printing.com/
They are a European company that moved into the US market a couple of years ago. I can vouch for their print quality and the prices are very reasonable. Fast turnarounds too.