I see that puzzler was trying to confuse me by talking about,

A3 size...

Google helped me find "Weights and Sizes of Papers". 

Just for our reference, I'll quote a bit of that page ...

Metric  Nearest US Equivalent
Name  mm         inches         Name        inches
====  =========  =============  ==========  =============

A8     53 x  74   2.07 x  2.91  Bus. card    2    x  3.5
A7     74 x 105   2.91 x  4.13  3 x 5        3    x  5
A6    105 x 148   4.13 x  5.83  Microfiche   4.13 x  5.83
A5    148 x 210   5.83 x  8.27  5 x 8        5    x  8
A4    210 x 297   8.27 x 11.69  A            8.5  x 11
A3    297 x 420  11.69 x 16.54  B           11    x 17

OK ... Now I know what you are talking about. 

A3 would be a little larger than 11 x 17. 

I have a Canon PIXMA IP5000 (and like it a lot) ... so I tend to suggest
a Canon printer. 

The Canon PIXMA Pro9000 (US) also Canon PIXMA Pro9000 (UK)...

Paper Sizes: Letter, Legal, 4"x 6", 4"x 8", 5"x 7", 8"x 10", 13"x 19", U.S. #10 Envelopes

Number of Nozzles: 768 x 8 colors (Photo Bk, C, M, Y, PC, PM, R, G); Total: 6,144

Print Resolution (Up to): Black: 4800 x 2400 dpi; Color: 4800 x 2400 dpi

MSRP $500 ... but available for $380 to $420 ... on the 'net. 

Here is a UK review that gives the price as  £296  (£347 inc VAT). 

You'll need to search for the best price. 

HTH

--
Martin