A few more words. Will try to explain what I have posted above , with a bit more detail :
A -" Epson 3800 or Canon IPF5000 or HP Z3100 , are all top of the line for image quality and you will not go wrong with either of them." :
Guess it was the year 2002 when I saw some professional prints made by Epson 2100. Couldn't believe a small desktop printer can print such a nice and quality picture . and it was the time that I understood big changes are on the way for printing industry. It has been several years from that observation and just in last few years , the progress on inkjet industry has been more amazing.
When you pass your initial set up and cost and learning curve with either of above printers , then the result is priceless.
For decades I have used pay to print labs . Not anymore. It is a great feeling to have a full control over your workflow. It is you and just you who knows what you have seen and how you want it printed. you will Also have access to hundreds of different media and your final cost will be less expensive for your prints after your initial set up. And you can not go wrong with either of the mentioned printers. The only question would be which one suits you better.
B - Have had experience with Epson printers . Not used 3800 so no comment on this model . It is a nice printer , with lots of happy users which will recommend it to you.
C - For Canon 5000 , it has been a good choice for me and still would be the choice for a 17" printer even if I did not have it.
Then why did not recommend it to you if I'm happy with mine ? because of all of what have been discussed in detail by John Hollenberg's review.
This is a professional , detailed and fair review and I agree with its content. Some people may see it negative . I see it positive and informative . If every printer had a wiki similar to the unofficial 5000 , would be great for users . John Hollenberg has managed and organized this wiki and it is a very helpful and supportive site. If it happened buying a 5000 , you will have lots of support of all kind from wiki participants.
D - "You may need Z3100-24" if you are mostly printing over 17". It is a great printer . just needs to realize that it does not have the convenience of cassette and might not be practical for small prints . It's designed for big prints and heavy usage."
Assuming Z-3100 is one of the best printers ever made , have ordered one and will be up and running in a few weeks.
But still I will stand by the above comment : It does not have the convenience of Epson3800 or Canon5000 for smaller prints or sheets . It has been designed for big prints.
E - "when you made up your mind about any printer, buy it from a reputable reseller "
If you don't want to have a unpleasant experience of buying from a funny reseller , buy it from somewhere with a good reputation of service and knowledge . This is very important , regardless of which brand or model you are buying . These are some of the reputable resellers or paper /ink suppliers with great reputation. The links are listed by alphabetical order. You can get more advise about your specific questions from them , as well .http://booksmartstudio.com/http://www.colorhq.com/http://itsupplies.com/http://shadesofpaper.com/
Regards - Avalan