How to arrange different UI input elements(checkboxes, radio inputs,etc) in Shiny?

1. 
   

   Based on user's selection my Shiny application should generated a variable number of checkbox and I would like to display them in a row/column format. (Shiny gives the horizontal and vertical option via inline argument but I want the display in matrix type format.) How you do that? Also, I would like to have them displayed in the user input area instead of the main panel right below user's selection box, selectInput.

   
   


2. 
   

   Is there a push button in Shiny that I can use instead checkbox?

   
   

Here are my scripts:

ui.R

library(shiny)
library(shinythemes)
shinyUI(fluidPage(theme = shinytheme("cerulean"),
  # Title
  headerPanel(title = "Run selection", windowTitle = "Run selection" ),

  sidebarLayout(
    sidebarPanel(

      selectInput(runName, paste0('Select your run'), choices = runs),

      lapply(runsRange, function(i) {
        checkboxGroupInput("selectRuns", i, choices = "", inline = TRUE)
            })
            ),

      mainPanel()
    )
  ))

server.R

library(shiny)
library(shinythemes)

shinyServer(function(input, output) {})