Moving To A Ten-Gallon

[hy3gons]

I currently have 2 male guppies in a 5.5 gallon tank. I have had them for almost 7 months and they have been very peaceful until recently. I am going to get a larger tank so I can stock more fish and hopefully end this problem, I just have a few questions.
 
My current filter is meant for tanks that are ten gallons or less, could I just switch it over to the new tank once it is cycled? Adding to that, can I cycle a tank without a filter?
 
How many male guppies will I be able to keep in a ten gallon? I change about 15-20% of the water every week and don't plan on doing any more or less.
 
Will my current guppies pick on/eat any new ones? New fish would probably be slightly smaller than the two I have now.
 
I don't plan on adding any real plants to the tank, but should I provide fake ones for shelter?
 
Finally, what kinds of guppies would you recommend adding? My two are Blonde Delta guppies, so they're orange and white and I would like to have more colors.

 

[eaglesaquarium]

I currently have 2 male guppies in a 5.5 gallon tank. I have had them for almost 7 months and they have been very peaceful until recently. I am going to get a larger tank so I can stock more fish and hopefully end this problem, I just have a few questions.
 
My current filter is meant for tanks that are ten gallons or less, could I just switch it over to the new tank once it is cycled? Adding to that, can I cycle a tank without a filter?
The filter you currently have is cycled for your current bioload.  You can move that over and be essentially 'instantly' cycled with the new tank.
You cannot 'cycle a tank' without a filter.  
 
How many male guppies will I be able to keep in a ten gallon? I change about 15-20% of the water every week and don't plan on doing any more or less.
An increased bioload would require more frequent or larger water changes.  I'd recommend 5 male guppies in the 10 gallon tank, with 25+% water changes weekly.
 
Will my current guppies pick on/eat any new ones? New fish would probably be slightly smaller than the two I have now.
Adding more male guppies will spread the aggression.  Adding 3 smaller guppies to the old guppies would go best if you add the new guppies to the tank first, THEN add the older guppies afterwards.
 
I don't plan on adding any real plants to the tank, but should I provide fake ones for shelter?
Decor like real or fake plants are important to give shelter and a place to retreat to when being picked on.  The more, the better.  I'd recommend some easy real plants like java fern and/or anubias plus some floating plants... but some large rocks, wood, and fake plants would work well also.
 
Finally, what kinds of guppies would you recommend adding? My two are Blonde Delta guppies, so they're orange and white and I would like to have more colors.
Any color morphs would be fine.